Device for maintaining and positioning harnesses on a turbo-jet engine

ABSTRACT

The device for positioning and maintaining electric harnesses on the casing of a turbo-jet engine comprises harness supports standardised for directions substantially perpendicular to the axis of the turbojet engine and harness supports standardised for directions substantially parallel to the axis of the turbo-jet engine.

[0001] The present invention relates to a device for positioning andmaintaining electric harnesses on the casing of a turbo-jet engine aswell as an assembly method of harnesses on the casing.

[0002] With reference to FIG. 1, a turbo-jet engine 1 includes a casing2, possibly composed of several parts according to its structure, whichenvelops the various components thereof, regardless whether they arerotational or not, such as for instance the blower, the compressor, thecombustion chamber, the turbine, the nozzle and the post-combustion, asthe case may be.

[0003] On the external surface of this casing 2, besides the fluidtransport ducts, are laid out numerous electric cable assemblies,designated electric harnesses 3 in the field of turbo-jet engines. Theseelectric harnesses supply in particular the various pieces of peripheralequipment of the turbo-jet engine 1.

[0004] The harnesses 3 are generally maintained on the casing 2 by sheetmetal collars or plates, whereon they are snapped at regular intervals,in order to be maintained solidly. The collars and plates are fixed orwelded to flanges or protrusions of the casing 2. The fastening pointsare defined on a case-to-case basis, relative to the harnesses 3 to bemaintained or to the urgency of possible replacement. Besides, everyharness element should be replaceable individually.

[0005] There results a non-standardised and hence very tedious assemblyof all the harnesses 3, which is detrimental in terms of cost and ofproduction cycle, but also of mass, because of the presence of numeroussheet metal parts.

[0006] The purpose of the invention is to remedy these shortcomings.

[0007] In this view, the present invention relates to a device forpositioning and maintaining electric harnesses on the casing of aturbo-jet engine, the casing forming a peripheral envelop around theaxis of the turbo-jet engine, characterised in that it comprises firstharness supports standardised for directions substantially perpendicularto the axis of the turbo-jet engine and second harness supportsstandardised for directions substantially parallel to the axis of theturbo-jet engine.

[0008] Preferably, the first harness supports standardised forsubstantially perpendicular directions include lugs forming a bodywherein housings are provided for maintaining harnesses.

[0009] Preferably still, the second harness supports standardised forsubstantially perpendicular directions include barrels with globallycylindrical body along which are provided housings for maintainingharnesses.

[0010] Advantageously, the barrels are fastened to a dummy duct mountedrigidly t the casing of the turbo-jet engine.

[0011] Other features and advantages of the invention will appear whenreading the following description of the preferred embodiment of thedevice of the invention, with reference to the appended drawings,whereon:

[0012]FIG. 1 is a perspective view of a turbo-jet engine;

[0013]FIG. 2 is a front perspective view of a lug of the device of theinvention;

[0014]FIG. 3 is a side perspective view of a lug of the device of theinvention, maintaining harnesses;

[0015]FIG. 4 is a schematic front perspective view of the casing of aturbo-jet engine whereon are attached lugs of the device of theinvention;

[0016]FIG. 5 is a schematic front perspective view of a first embodimentof a barrel of the device of the invention;

[0017]FIG. 6 is a side perspective view of FIG. 5, maintainingharnesses;

[0018]FIG. 7 is a schematic front perspective view of a secondembodiment of a barrel of the device of the invention;

[0019]FIG. 8 is a side perspective view of FIG. 7, maintainingharnesses;

[0020]FIG. 9 is a side perspective view of a dummy duct of the device ofthe invention, and

[0021]FIG. 10 is a perspective view of the casing of a turbo-jet enginewhereon are attached the duct and the barrels of the device of theinvention.

[0022] With reference to FIG. 1, a turbo-jet engine 1 includes a casing2 enveloping its various components. This casing 2 extends globally in aperipheral pattern around the axis 4 of the turbo-jet engine 1.Harnesses are laid out at the periphery of the casing 2. FIG. 1represents a turbo-jet engine of the previous art, at the surface ofwhich the harnesses 3 are arranged without any apparent order. Thepurpose of the device of the invention is to tidy up the arrangement ofthe harnesses 3.

[0023] The device of the invention includes lugs 10 one of which isrepresented on FIG. 2. The lug 10 includes a body 11, globallyparallelepiped in shape, preferably of plastic material. On its lowerface 12, the lug 10 includes two fastening tabs 14, 14′. In its upperportion 13 are provided housings 15 a, 15 b, 15 c, 15 d whereof theshape matches that of the harnesses 3. The housings 15 a, 15 b, 15 c, 15d are formed by plastics technology moulding of the lug 10. Their shapemay vary from lug to another, relative to the use which is made of thelatter, the adaptation being made by ad hoc configuration of theplastics technology moulding.

[0024] With reference to FIG. 3, the housings 15 a, 15 b, 15 c, 15 d areintended for receiving harnesses 3 a, 3 b, 3 c, 3 d, respectively. Theharnesses 3 a, 3 b, 3 c, 3 d are in the form of cylindrical pipes madeof insulating material wherein are inserted the conducting wires. Moreprecisely, each harness, 3 a, 3 b, 3 c and 3 d, includes a ring forminga cylindrical bearing, 30 a, 30 b, 30 c, 30 d, respectively, inserted inthe corresponding housing 15 a, 15 b, 15 c, 15 d, and whereof thediameter is adapted to that of the housing 15 a, 15 b, 15 c, 15 dsupporting said bearing. Each ring 30 a, 30 b, 30 c, 30 d comprises ateach of its ends a rim of diameter greater than that of the housing 15a, 15 b, 15 c, 15 d wherein it is inserted, in order to prevent anymovement of the harness 3 a, 3 b, 3 c, 3 d in longitudinal translation.

[0025]FIG. 4 shows lugs 10′, 10′, 10″ of the type of that describedpreviously, attached to the casing 2 of the turbo-jet engine 1 in orderto maintain the harnesses 3 a, 3 b, 3 c, 3 d in position. In theembodiment of the device of the invention described herein, the lugs 10,10′, 10″ are intended for holding the harnesses 3 a, 3 b, 3 c, 3 d inthe peripheral directions substantially perpendicular to the axis 4 ofthe turbo-jet engine 1.

[0026] The lugs 10, 10′, 10″ may be attached to the casing 2 in variousways. It is here chosen to attache them to circumferential flanges 16 ofthe casing 2, inasmuch as they are tangent to the peripheral directionsperpendicular to the axis 4. Said flanges 16 may be of straight orT-shaped section, for example. A screw-nut system 17 ensures attachmentof the tabs 14, wherewith the lugs 10, 10′, 10″ are fitted, to theflanges 16. Quick-release fastening means may also be used, for exampleof snap-on type, for easy and straightforward positioning andreplacement of the lugs 10, 10′, 10″.

[0027] The harnesses 3 a, 3 b, 3 c, 3 d are not, a priori, all ofidentical diameter; the various housings of each lug 10, 10′, 10″ aresized accordingly, by appropriate sizing of the plastics technologymoulds.

[0028] The lugs 10, 10′, 10″ are mounted on the casing 2 in relation tothe arrangement of the harnesses 3 a, 3 b, 3 c, 3 d at the periphery ofthe casing 2, which may be pre-established. It is therefore possible toprovide bundles of harnesses 3 a, 3 b, 3 c, 3 d laid out parallel to oneanother, for easier assembly in the production line, readability oftheir arrangement, but also easier replacement thereof. Moreover, it ispossible to standardise the lugs 10, 10′, 10″ relative to the harnesses,themselves standardised, that they are supposed to support; inparticular, such standardisation could be performed for all the modelsof turbo-jet engine of the same manufacturer, possibly for models ofturbo-jet engines of different manufacturers, enabling globalisation ofthe definition of the arrangements of the harnesses on a turbo-jetengine.

[0029] The selection of the arrangement of the harnesses into bundlesmay only be made, generally, over the whole path travelled, on theperiphery of the casing 2, by each harness in particular. Thus, the lugs10, 10′, 10″ of the invention are used as much as possible along thepaths shared by the harnesses of the same bundle, and when a particularharness must deviate from the circumferential ‘route’ provided, it isheld on the casing 2 until its final attachment point using conventionalholding means, made of sheet metal metal, for example.

[0030] The device of the invention also comprises barrels, such as thebarrel 20 represented on FIG. 5. The barrel 20 includes a body 21,globally cylindrical in shape, preferably of plastic material. Thebarrel 20 includes a central bore 22 with a radial recess 23 extendingfrom its centre to its lower peripheral portion, and delineating at thelatter two fastening tabs 24, 24′. On the remainder of its peripheralportion, the barrel comprises housings 25 a, 25 b, 25 c, 25 d, 25 e, 25f with radial opening for the harnesses 3. The housings 25 a, 25 b, 25c, 25 d, 25 e, 25 f are formed during plastics technology moulding ofthe barrel 20. Their shape may vary from one barrel to the other, inrelation to the usage made thereof, any matching being made by ad hocconfiguration of the plastics technology mould.

[0031] With reference to FIG. 6, the barrel 20 is attached to a dummyduct 40. Like the flanges 16 supporting the lugs 10, 10′, 10″ to thecasing 2, the duct 40 maintains the barrel 20 fixedly with respect tothe casing 2, with which it is integral. This duct 40, designated hereas dummy inasmuch as it is not intended for guiding a fluid any way,forms hence the support of the barrel 20 on the casing 2. According tothe arrangement chosen for the harnesses 3, the duct 40 may be chosenamong the duct already existing and used for guiding fluids of theturbo-jet engine 1.

[0032] The barrel 20 is in this embodiment attached to the duct 40 by ascrew/nut system 26 co-operating with the tabs 24, 24′. The duct 40includes moreover a ring 41 co-operating with the bore 22. According toa variation, a quick-release fastening system is used. Regardless whatit may be, the attachment system should ensure longitudinal androtational translation maintenance of the barrel 20 on the duct 40.

[0033] Same as for the barrels 10, 10′, 10″, the housings 25 a, 25 b, 25c, 25 d, 25 e, 25 f of the barrel 20 are intended for receivingharnesses 3′a, 3′b, 3′c, 3′d, 3′e, 3′f, respectively. As previously,each harness 3′a, 3′b, 3′c, 3′d, 3′e, 3′f includes a ring matched itshousing 25 a, 25 b, 25 c, 25 d, 25 e, 25 f, as well as longitudinalmaintenance rims.

[0034] The barrel 20 of FIG. 5 comprises six housings 25 a, 25 b, 25 c,25 d, 25 e, 25 f. However, a smaller number of housing may be necessary,if a smaller number of harnesses 3 are intended for arrangement alongthe duct 40 whereon the barrel 20 is attached.

[0035] It is however preferable to have standardised type of plasticstechnology mould for the barrels, globally independent of the number ofhousings necessary, i.e. a mould which is globally cylindrical in shape,identical regardless of the number of housings provided.

[0036] The number of housings may be selected during moulding byarranging appropriate caches inside the plastics technology mould. Thelatter enables to obtain the maximum number of housings necessary, overall the paths followed by the harnesses at the periphery of theturbo-jet engine, with the option of removing some of them. Thispossibility is compulsory, since it is not acceptable to leave housingsempty. Indeed, the technician operating on the turbo-jet engine must besure that all the harnesses have been placed indeed, an empty housingindicating that, supposedly, a harness has been left aside.

[0037] There is thus represented, on FIG. 7, a barrel 120, coming fromthe same plastics technology mould as the barrel 20 of FIG. 5, whereasthe mould has been modified in order to give the housings a differentconfiguration. Thus, the barrel 120 includes four housings 125 a, 125 c,125 d, 125 e for harnesses, which are at the same angular position onthe barrel 120 as the housings 25 a, 25 c, 25 d, 25 e of the barrel 20,but here with different diameters for some of them. Moreover, the sites125 b, 125 f, corresponding to the sites of the housings 25 b, 25 f onthe barrel 20, have been emptied. It is therefore possible to noticevisually that they are not intended for supporting a harness.

[0038] It may also be contemplated that the sites not intended forsupporting a harness are not emptied, but filled with matter.

[0039] It suffices to provide a mould whereof the core comprisesremovable or adjustable portions.

[0040]FIG. 8 shows a barrel 120 attached in the same way as the barrel20 to the duct 40, here using a screw-nut system 126, which could bereplaced by a quick-release fastening system. The housings 125 a, 125 c,125 d, 125 e support harnesses 103′a, 103′c, 103′d, 103′e, by means ofrings, in the same way as in the case of the barrel 20.

[0041] With reference to FIG. 9, the dummy duct 40 is attached to thecasing 2 by means of fastening tabs 42, 42′, 42″. It supports rings orsleeves 41 a, 41 b, 41 c, 41 d spaced regularly over its length andintended to receive barrels of the type of those described above. OnFIG. 9, the duct 40 is represented on its own, without any otherelement, but it corresponds to the duct 40 of FIG. 10, isolated from theother elements for easier understanding of its structure.

[0042] With reference to FIG. 10, the duct 40 of FIG. 9 is attached tothe casing 2 by means of its fastening tabs 42, 42′, 42″. The rings 41 band 41 c support the barrels 120 and 20, respectively. The rings 41 aand 41 d support two other barrels 220 and 320, shaped relative to theharnesses 3 to be supported at this location. In such a case, thebarrels 220 and 320 comprise respectively five and six housings forharnesses.

[0043] The duct 40 and the barrels 20, 120, 220, 320, which it supports,form therefore a privileged path for the harnesses 3. In the embodimentof the device of the invention described here, the barrels are intendedfor maintaining the harnesses in the peripheral directions,substantially parallel to the axis 4 of the turbo-jet engine.

[0044] The arrangement of the harnesses 3 may be foreseen during thedevelopment stage of the engine, which enables to design thecorresponding barrels 20, 120, 220, 320 and to place them on the duct40. FIG. 10 is a good illustration of this approach. It has been notablymentioned above that the harnesses cannot follow, from the beginning tothe end of their paths, pre-established runs along the ducts 40 or theflanges 16 and they do so over the longest possible distance beforedeviating them towards their destination, possibly supported byconventional supporting means. This situation is that of the harnesses103′c and 103′d, which after having been supported by the barrel 220 andthe barrel 120, deviate from the trajectory of the duct 40 in order tobe connected to the equipment 50 for which they are intended.

[0045]FIG. 10 shows the presence of the flange 16 of FIG. 4, whereas theportion of casing 2 represented is substantially the same on bothFigures. The lugs 10, 10′, 10″ and the harnesses 3 a, 3 b, 3 c, 3 dwhich they support, are however not represented for clarity purposes ofthe description of the barrels, but it is easy to imagine the wholedevice of the invention, i.e. the lugs on their flange and the barrelson their duct, by superimposing FIGS. 4 and 10.

[0046] The pre-established paths of the harnesses may involve, for thesame harness, at the same time, on the one hand, portions of pathrunning along the flanges, supported by lugs, on the other hand,portions of path along (dummy) ducts, supported by barrels. Such is thecase for instance, of the harness 3′f of FIG. 6, which after a portionof path along the duct 40, supported by the barrels 20 and 320, changesdirection to follow a trajectory perpendicular to the axis 4 of theturbo-jet engine, notably supported by a lug 100, of a type slightlydifferent from the lug 10 of FIG. 2, but standardised in the same way.

[0047] It should be noted that, like the barrels, the lugs are modularas regards the number and the dimensions of the housings that theycomprise. Thus, from a standardised model of lug, it is possible, bysimple arrangement of appropriate caches in the core of the plasticstechnology mould, to remove or to add a housing, or to change thedimensions thereof. In particular, an unused housing site is eitherfilled with matter or emptied explicitly, i.e. so that an observer maydetect with certainty that no harness may be inserted into the recess.

[0048] The lugs and the barrels are derived from plastics technology.Consequently, it is very simple to adapt their structure and theircomposition to the usage made thereof, for example according to whichductile or rigid parts are required. It is notably possible that theseparts are composed of several materials with different characteristics,comprise ductile slots or integrate embedded metal elements.

[0049] In the embodiment described of the device of the invention, lugsare used for maintaining harness in peripheral direction substantiallyperpendicular to the axis of the turbo-jet engine and barrels for theperipheral direction substantially parallel to the axis of the turbo-jetengine. The flanges extending at the circumference of the casing of theturbo-jet engine are used advantageously for supporting harnessmaintenance elements.

[0050] Any other type of harness maintenance element could be used. Itis notably thinkable to adapt the geometry of the barrels to theflanges.

[0051] Thanks to the device of the invention and inasmuch as the extremepoints of the harnesses are known, it is possible to define beforehand asimple configuration of the harnesses. Indeed, from one point toanother, a trajectory may always be broken down, at least over itsgreatest part, into the sum of two (or more) peripheral trajectories,one which is substantially perpendicular and the other which issubstantially parallel to the axis of the turbo-jet engine.

[0052] Thus, at the time of final installation of the engine, theassemblies composed of the harnesses and of their supporting elementsmay be installed more or less as a single block, at least in astandardised fashion, automatically and easily, and not, as is the casetoday, one part after the other.

[0053] Besides, the maintenance of the turbo-jet engine is vastlysimplified. First of all, the arrangements of the harnesses are far morestraightforward. Moreover, each supporting element may be mounted ordismantled individually. The same goes for the harnesses, let alonecertain harness bundles, which thanks to the invention may be mounted ordismantled as a whole. Additionally, it goes without saying that, if thesituation requires so, a conventional attachment means, such as a collaror a plate, may be added at any time.

1- A device for positioning and maintaining electric harnesses on thecasing of a turbo-jet engine, the casing forming a peripheral enveloparound the axis of the turbo-jet engine, characterised in that itcomprises harness supports standardised for directions substantiallyperpendicular to the axis of the turbo-jet engine and harness supportsstandardised for directions substantially parallel to the axis of theturbo-jet engine. 2- A device according to claim 1, wherein the harnesssupports standardised for directions substantially perpendicular includeat least one lug with an elongated body wherein is provided at least onehousing for maintaining harnesses. 3- A device according to claim 2,wherein the lug is at least partially composed of plastic material. 4- Adevice according to claim 2, whereof the lug includes a means forattachment to a flange of the casing of the turbo-jet engine. 5- Adevice according to claim 1, wherein the harness supports standardisedfor directions substantially parallel to the axis of the engine compriseat least one barrel with a cylindrical body wherein is received at leastone housing for maintaining harnesses. 6- A device according to claim 5,wherein the barrel is at least partially composed of plastic material.7- A device according to claim 5, wherein the barrel includes a meansfor attachment to a duct mounted fixedly on the casing of the turbo-jetengine. 8- A device according to claim 7, wherein the duct includes atleast one ring supporting a barrel. 9- A device according to claim 7,wherein the duct is a dummy duct. 10- A device according to claim 1.,wherein the supports of harnesses are attached by means of screw-nutsystems. 11- A device according to claim 1, wherein the harness supportsare attached by means of quick-release fastening systems. 12- A methodfor assembling electric harnesses of a turbo-jet engine, the casingforming a peripheral envelop around the axis of the turbo-jet engine,characterised in that the harness are arranged at least partially alongdirections substantially perpendicular and parallel to the axis of theturbo-jet engine. 13- A method for arranging electric harnessesaccording to claim 12, wherein the harnesses are attached using a devicefor positioning and maintaining harnesses according to one of the claims1 to
 11. 14- A set of harnesses and of harness supports comprising thefeatures of the supports of one of the claims 1 to 11, wherein theharnesses comprise rings intended to be housed in the harness supports.